view src/http/v2/ngx_http_v2_module.c @ 7094:c7d4017c8876

Secure link: fixed stack buffer overflow. When secure link checksum has length of 23 or 24 bytes, decoded base64 value could occupy 17 or 18 bytes which is more than 16 bytes previously allocated for it on stack. The buffer overflow does not have any security implications since only one local variable was corrupted and this variable was not used in this case. The fix is to increase buffer size up to 18 bytes. Useless buffer size initialization is removed as well.
author Roman Arutyunyan <arut@nginx.com>
date Tue, 22 Aug 2017 21:22:59 +0300
parents 2a288909abc6
children 641306096f5b
line wrap: on
line source


/*
 * Copyright (C) Nginx, Inc.
 * Copyright (C) Valentin V. Bartenev
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>
#include <ngx_http_v2_module.h>


static ngx_int_t ngx_http_v2_add_variables(ngx_conf_t *cf);

static ngx_int_t ngx_http_v2_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data);

static ngx_int_t ngx_http_v2_module_init(ngx_cycle_t *cycle);

static void *ngx_http_v2_create_main_conf(ngx_conf_t *cf);
static char *ngx_http_v2_init_main_conf(ngx_conf_t *cf, void *conf);
static void *ngx_http_v2_create_srv_conf(ngx_conf_t *cf);
static char *ngx_http_v2_merge_srv_conf(ngx_conf_t *cf, void *parent,
    void *child);
static void *ngx_http_v2_create_loc_conf(ngx_conf_t *cf);
static char *ngx_http_v2_merge_loc_conf(ngx_conf_t *cf, void *parent,
    void *child);

static char *ngx_http_v2_recv_buffer_size(ngx_conf_t *cf, void *post,
    void *data);
static char *ngx_http_v2_pool_size(ngx_conf_t *cf, void *post, void *data);
static char *ngx_http_v2_preread_size(ngx_conf_t *cf, void *post, void *data);
static char *ngx_http_v2_streams_index_mask(ngx_conf_t *cf, void *post,
    void *data);
static char *ngx_http_v2_chunk_size(ngx_conf_t *cf, void *post, void *data);
static char *ngx_http_v2_spdy_deprecated(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);


static ngx_conf_post_t  ngx_http_v2_recv_buffer_size_post =
    { ngx_http_v2_recv_buffer_size };
static ngx_conf_post_t  ngx_http_v2_pool_size_post =
    { ngx_http_v2_pool_size };
static ngx_conf_post_t  ngx_http_v2_preread_size_post =
    { ngx_http_v2_preread_size };
static ngx_conf_post_t  ngx_http_v2_streams_index_mask_post =
    { ngx_http_v2_streams_index_mask };
static ngx_conf_post_t  ngx_http_v2_chunk_size_post =
    { ngx_http_v2_chunk_size };


static ngx_command_t  ngx_http_v2_commands[] = {

    { ngx_string("http2_recv_buffer_size"),
      NGX_HTTP_MAIN_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_MAIN_CONF_OFFSET,
      offsetof(ngx_http_v2_main_conf_t, recv_buffer_size),
      &ngx_http_v2_recv_buffer_size_post },

    { ngx_string("http2_pool_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_v2_srv_conf_t, pool_size),
      &ngx_http_v2_pool_size_post },

    { ngx_string("http2_max_concurrent_streams"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_v2_srv_conf_t, concurrent_streams),
      NULL },

    { ngx_string("http2_max_requests"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_v2_srv_conf_t, max_requests),
      NULL },

    { ngx_string("http2_max_field_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_v2_srv_conf_t, max_field_size),
      NULL },

    { ngx_string("http2_max_header_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_v2_srv_conf_t, max_header_size),
      NULL },

    { ngx_string("http2_body_preread_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_v2_srv_conf_t, preread_size),
      &ngx_http_v2_preread_size_post },

    { ngx_string("http2_streams_index_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_num_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_v2_srv_conf_t, streams_index_mask),
      &ngx_http_v2_streams_index_mask_post },

    { ngx_string("http2_recv_timeout"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_v2_srv_conf_t, recv_timeout),
      NULL },

    { ngx_string("http2_idle_timeout"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_msec_slot,
      NGX_HTTP_SRV_CONF_OFFSET,
      offsetof(ngx_http_v2_srv_conf_t, idle_timeout),
      NULL },

    { ngx_string("http2_chunk_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_conf_set_size_slot,
      NGX_HTTP_LOC_CONF_OFFSET,
      offsetof(ngx_http_v2_loc_conf_t, chunk_size),
      &ngx_http_v2_chunk_size_post },

    { ngx_string("spdy_recv_buffer_size"),
      NGX_HTTP_MAIN_CONF|NGX_CONF_TAKE1,
      ngx_http_v2_spdy_deprecated,
      NGX_HTTP_MAIN_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("spdy_pool_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_http_v2_spdy_deprecated,
      NGX_HTTP_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("spdy_max_concurrent_streams"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_http_v2_spdy_deprecated,
      NGX_HTTP_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("spdy_streams_index_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_http_v2_spdy_deprecated,
      NGX_HTTP_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("spdy_recv_timeout"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_http_v2_spdy_deprecated,
      NGX_HTTP_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("spdy_keepalive_timeout"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_http_v2_spdy_deprecated,
      NGX_HTTP_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("spdy_headers_comp"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_CONF_TAKE1,
      ngx_http_v2_spdy_deprecated,
      NGX_HTTP_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("spdy_chunk_size"),
      NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1,
      ngx_http_v2_spdy_deprecated,
      NGX_HTTP_LOC_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};


static ngx_http_module_t  ngx_http_v2_module_ctx = {
    ngx_http_v2_add_variables,             /* preconfiguration */
    NULL,                                  /* postconfiguration */

    ngx_http_v2_create_main_conf,          /* create main configuration */
    ngx_http_v2_init_main_conf,            /* init main configuration */

    ngx_http_v2_create_srv_conf,           /* create server configuration */
    ngx_http_v2_merge_srv_conf,            /* merge server configuration */

    ngx_http_v2_create_loc_conf,           /* create location configuration */
    ngx_http_v2_merge_loc_conf             /* merge location configuration */
};


ngx_module_t  ngx_http_v2_module = {
    NGX_MODULE_V1,
    &ngx_http_v2_module_ctx,               /* module context */
    ngx_http_v2_commands,                  /* module directives */
    NGX_HTTP_MODULE,                       /* module type */
    NULL,                                  /* init master */
    ngx_http_v2_module_init,               /* init module */
    NULL,                                  /* init process */
    NULL,                                  /* init thread */
    NULL,                                  /* exit thread */
    NULL,                                  /* exit process */
    NULL,                                  /* exit master */
    NGX_MODULE_V1_PADDING
};


static ngx_http_variable_t  ngx_http_v2_vars[] = {

    { ngx_string("http2"), NULL,
      ngx_http_v2_variable, 0, 0, 0 },

      ngx_http_null_variable
};


static ngx_int_t
ngx_http_v2_add_variables(ngx_conf_t *cf)
{
    ngx_http_variable_t  *var, *v;

    for (v = ngx_http_v2_vars; v->name.len; v++) {
        var = ngx_http_add_variable(cf, &v->name, v->flags);
        if (var == NULL) {
            return NGX_ERROR;
        }

        var->get_handler = v->get_handler;
        var->data = v->data;
    }

    return NGX_OK;
}


static ngx_int_t
ngx_http_v2_variable(ngx_http_request_t *r,
    ngx_http_variable_value_t *v, uintptr_t data)
{

    if (r->stream) {
#if (NGX_HTTP_SSL)

        if (r->connection->ssl) {
            v->len = sizeof("h2") - 1;
            v->valid = 1;
            v->no_cacheable = 0;
            v->not_found = 0;
            v->data = (u_char *) "h2";

            return NGX_OK;
        }

#endif
        v->len = sizeof("h2c") - 1;
        v->valid = 1;
        v->no_cacheable = 0;
        v->not_found = 0;
        v->data = (u_char *) "h2c";

        return NGX_OK;
    }

    *v = ngx_http_variable_null_value;

    return NGX_OK;
}


static ngx_int_t
ngx_http_v2_module_init(ngx_cycle_t *cycle)
{
    return NGX_OK;
}


static void *
ngx_http_v2_create_main_conf(ngx_conf_t *cf)
{
    ngx_http_v2_main_conf_t  *h2mcf;

    h2mcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_v2_main_conf_t));
    if (h2mcf == NULL) {
        return NULL;
    }

    h2mcf->recv_buffer_size = NGX_CONF_UNSET_SIZE;

    return h2mcf;
}


static char *
ngx_http_v2_init_main_conf(ngx_conf_t *cf, void *conf)
{
    ngx_http_v2_main_conf_t *h2mcf = conf;

    ngx_conf_init_size_value(h2mcf->recv_buffer_size, 256 * 1024);

    return NGX_CONF_OK;
}


static void *
ngx_http_v2_create_srv_conf(ngx_conf_t *cf)
{
    ngx_http_v2_srv_conf_t  *h2scf;

    h2scf = ngx_pcalloc(cf->pool, sizeof(ngx_http_v2_srv_conf_t));
    if (h2scf == NULL) {
        return NULL;
    }

    h2scf->pool_size = NGX_CONF_UNSET_SIZE;

    h2scf->concurrent_streams = NGX_CONF_UNSET_UINT;
    h2scf->max_requests = NGX_CONF_UNSET_UINT;

    h2scf->max_field_size = NGX_CONF_UNSET_SIZE;
    h2scf->max_header_size = NGX_CONF_UNSET_SIZE;

    h2scf->preread_size = NGX_CONF_UNSET_SIZE;

    h2scf->streams_index_mask = NGX_CONF_UNSET_UINT;

    h2scf->recv_timeout = NGX_CONF_UNSET_MSEC;
    h2scf->idle_timeout = NGX_CONF_UNSET_MSEC;

    return h2scf;
}


static char *
ngx_http_v2_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
{
    ngx_http_v2_srv_conf_t *prev = parent;
    ngx_http_v2_srv_conf_t *conf = child;

    ngx_conf_merge_size_value(conf->pool_size, prev->pool_size, 4096);

    ngx_conf_merge_uint_value(conf->concurrent_streams,
                              prev->concurrent_streams, 128);
    ngx_conf_merge_uint_value(conf->max_requests, prev->max_requests, 1000);

    ngx_conf_merge_size_value(conf->max_field_size, prev->max_field_size,
                              4096);
    ngx_conf_merge_size_value(conf->max_header_size, prev->max_header_size,
                              16384);

    ngx_conf_merge_size_value(conf->preread_size, prev->preread_size, 65536);

    ngx_conf_merge_uint_value(conf->streams_index_mask,
                              prev->streams_index_mask, 32 - 1);

    ngx_conf_merge_msec_value(conf->recv_timeout,
                              prev->recv_timeout, 30000);
    ngx_conf_merge_msec_value(conf->idle_timeout,
                              prev->idle_timeout, 180000);

    return NGX_CONF_OK;
}


static void *
ngx_http_v2_create_loc_conf(ngx_conf_t *cf)
{
    ngx_http_v2_loc_conf_t  *h2lcf;

    h2lcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_v2_loc_conf_t));
    if (h2lcf == NULL) {
        return NULL;
    }

    h2lcf->chunk_size = NGX_CONF_UNSET_SIZE;

    return h2lcf;
}


static char *
ngx_http_v2_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child)
{
    ngx_http_v2_loc_conf_t *prev = parent;
    ngx_http_v2_loc_conf_t *conf = child;

    ngx_conf_merge_size_value(conf->chunk_size, prev->chunk_size, 8 * 1024);

    return NGX_CONF_OK;
}


static char *
ngx_http_v2_recv_buffer_size(ngx_conf_t *cf, void *post, void *data)
{
    size_t *sp = data;

    if (*sp <= 2 * NGX_HTTP_V2_STATE_BUFFER_SIZE) {
        return "value is too small";
    }

    return NGX_CONF_OK;
}


static char *
ngx_http_v2_pool_size(ngx_conf_t *cf, void *post, void *data)
{
    size_t *sp = data;

    if (*sp < NGX_MIN_POOL_SIZE) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "the pool size must be no less than %uz",
                           NGX_MIN_POOL_SIZE);

        return NGX_CONF_ERROR;
    }

    if (*sp % NGX_POOL_ALIGNMENT) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "the pool size must be a multiple of %uz",
                           NGX_POOL_ALIGNMENT);

        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}


static char *
ngx_http_v2_preread_size(ngx_conf_t *cf, void *post, void *data)
{
    size_t *sp = data;

    if (*sp > NGX_HTTP_V2_MAX_WINDOW) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "the maximum body preread buffer size is %uz",
                           NGX_HTTP_V2_MAX_WINDOW);

        return NGX_CONF_ERROR;
    }

    return NGX_CONF_OK;
}


static char *
ngx_http_v2_streams_index_mask(ngx_conf_t *cf, void *post, void *data)
{
    ngx_uint_t *np = data;

    ngx_uint_t  mask;

    mask = *np - 1;

    if (*np == 0 || (*np & mask)) {
        return "must be a power of two";
    }

    *np = mask;

    return NGX_CONF_OK;
}


static char *
ngx_http_v2_chunk_size(ngx_conf_t *cf, void *post, void *data)
{
    size_t *sp = data;

    if (*sp == 0) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "the http2 chunk size cannot be zero");

        return NGX_CONF_ERROR;
    }

    if (*sp > NGX_HTTP_V2_MAX_FRAME_SIZE) {
        *sp = NGX_HTTP_V2_MAX_FRAME_SIZE;
    }

    return NGX_CONF_OK;
}


static char *
ngx_http_v2_spdy_deprecated(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                       "invalid directive \"%V\": ngx_http_spdy_module "
                       "was superseded by ngx_http_v2_module", &cmd->name);

    return NGX_CONF_OK;
}